Identification of the principal neuropeptide MIP and its action pathway in larval settlement of the echiuran worm Urechis unicinctus.

BACKGROUND: Larval settlement and metamorphosis represent critical events in the life history of marine benthic animals. Myoinhibitory peptide (MIP) plays a pivotal role in larval settlement of marine invertebrates. However, the molecular mechanisms of MIP involved in this process are not well understood. RESULTS: In this study, we evaluated the effects of thirteen MIP mature peptides on triggering the larval settlement of Urechis unicinctus (Xenopneusta, Urechidae), and determined that MIP2 was the principal neuropeptide. Transcriptomic analysis was employed to identify differentially expressed genes (DEGs) between the MIP2-treated larvae and normal early-segmentation larvae. Both cAMP and calcium signaling pathways were enriched in the DEGs of the MIP2-treated larvae, and two neuropeptide receptor genes (Spr, Fmrfar) were up-regulated in the MIP2-treated larvae. The activation of the SPR-cAMP pathway by MIP2 was experimentally validated in HEK293T cells. Furthermore, fourteen cilia-related genes, including Tctex1d2, Cfap45, Ift43, Ift74, Ift22, Cav1 and Mns1, etc. exhibited down-regulated expression in the MIP2-treated larvae. Whole-mount in situ hybridization identified two selected ciliary genes, Tctex1d2 and Cfap45, were specially expressed in circumoral ciliary cells of the early-segmentation larvae. Knocking down Tctex1d2 mRNA levels by in vivo RNA interference significantly increased the larval settlement rate. CONCLUSION: Our findings suggest that MIP2 inhibits the function of the cilia-related genes, such as Tctex1d2, through the SPR-cAMP-PKA pathway, thereby inducing larval settlement in U. unicinctus. The study contributes important data to the understanding of neuropeptide regulation in larval settlement.

Genome-wide profiling of DNA methylome and transcriptome reveals epigenetic regulation of Urechis unicinctus response to sulfide stress.

Sulfide is a well-known environmental pollutant that can have detrimental effects on most organisms. However, few metazoans living in sulfide-rich environments have developed mechanisms to tolerate and adapt to sulfide stress. Epigenetic mechanisms, including DNA methylation, have been shown to play a vital role in environmental stress adaptation. Nevertheless, the precise function of DNA methylation in biological sulfide adaptation remains unclear. Urechis unicinctus, a benthic organism inhabiting sulfide-rich intertidal environments, is an ideal model organism for studying adaptation to sulfide environments. In this study, we conducted a comprehensive analysis of the DNA methylome and transcriptome of U. unicinctus after exposure to 50 µM sulfide. The results revealed dynamic changes in the DNA methylation (5-methylcytosine) landscape in response to sulfide stress, with U. unicinctus exhibiting elevated DNA methylation levels following stress exposure. Integrating differentially expressed genes (DEGs) and differentially methylated regions (DMRs), we identified a crucial role of gene body methylation in predicting gene expression. Furthermore, using a DNA methyltransferase inhibitor, we validated the involvement of DNA methylation in the sulfide stress response and the gene regulatory network influenced by DNA methylation. The results indicated that by modulating DNA methylation levels during sulfide stress, the expression of glutathione S-transferase, glutamyl aminopeptidase, and cytochrome c oxidase could be up-regulated, thereby facilitating the metabolism and detoxification of exogenous sulfides. Moreover, DNA methylation was found to regulate and enhance the oxidative phosphorylation pathway, including NADH dehydrogenase, isocitrate dehydrogenase, and ATP synthase. Additionally, DNA methylation influenced the regulation of Cytochrome P450 and macrophage migration inhibitory factor, both of which are closely associated with oxidative stress and stress resistance. Our findings not only emphasize the role of DNA methylation in sulfide adaptation but also provide novel insights into the potential mechanisms through which marine organisms adapt to environmental changes.

Transcatheter closure of atrial septal defects with absent aortic rim and the predictors of right atrial reverse remodelingTranscatheter closure of atrial septal defects with absent aortic rim and the predictors of right atrial reverse remodeling: 5 years experience in China.

【Abstract】 Aim: To investigate the safety of interventional therapy in patients with secondary atrial septal defect (atrial septal defect, ASD) with complete aortic rim deficiency and explore the predictors of right atrial non-reverse remodeling. METHODS: 1011 patients with ASD who underwent transcatheter closure in the Department of Cardiology, Zhongshan Hospital affiliated to Fudan University from June 2017 to June 2022 were enrolled in the study. They were divided into a complete aortic rim deficiency group and without absent aortic rim group. Furthermore, patients who had an enlarged right atrial in the absent aortic rim group were divided into two sub-groups according to whether their right atrial reversed remodeling post-procedure. Multivariate logistic regression was used to determine the predictors of right atrial reversed remodeling. RESULTS: During the 1-year follow-up, no major operative complications occurred in all patients with the absence of an aortic rim and a normal edge. After the operation, the right heart remodeling was significantly reversed, multivariate logistic regression analysis was performed and found that preoperative without coronary heart disease, lower plasma creatinine level, and larger RA and RV dimension were predictive factors for the reverse of right atrial remodeling after treatment. CONCLUSION: Transcatheter closure of ASD with complete aortic rim deficiency is safe and feasible. The patients without coronary heart disease, the lower the creatinine value and the less tricuspid regurgitation before an operation, the more improvement of right atrial remodeling after the operation.

Medical Management of Pulmonary Arterial Hypertension: Current Approaches and Investigational Drugs.

Pulmonary arterial hypertension (PAH) is a malignant pulmonary vascular syndrome characterized by a progressive increase in pulmonary vascular resistance and pulmonary arterial pressure, which eventually leads to right heart failure and even death. Although the exact mechanism of PAH is not fully understood, pulmonary vasoconstriction, vascular remodeling, immune and inflammatory responses, and thrombosis are thought to be involved in the development and progression of PAH. In the era of non-targeted agents, PAH had a very dismal prognosis with a median survival time of only 2.8 years. With the deep understanding of the pathophysiological mechanism of PAH as well as advances in drug research, PAH-specific therapeutic drugs have developed rapidly in the past 30 years, but they primarily focus on the three classical signaling pathways, namely the endothelin pathway, nitric oxide pathway, and prostacyclin pathway. These drugs dramatically improved pulmonary hemodynamics, cardiac function, exercise tolerance, quality of life, and prognosis in PAH patients, but could only reduce pulmonary arterial pressure and right ventricular afterload to a limited extent. Current targeted agents delay the progression of PAH but cannot fundamentally reverse pulmonary vascular remodeling. Through unremitting efforts, new therapeutic drugs such as sotatercept have emerged, injecting new vitality into this field. This review comprehensively summarizes the general treatments for PAH, including inotropes and vasopressors, diuretics, anticoagulants, general vasodilators, and anemia management. Additionally, this review elaborates the pharmacological properties and recent research progress of twelve specific drugs targeting three classical signaling pathways, as well as dual-, sequential triple-, and initial triple-therapy strategies based on the aforementioned targeted agents. More crucially, the search for novel therapeutic targets for PAH has never stopped, with great progress in recent years, and this review outlines the potential PAH therapeutic agents currently in the exploratory stage to provide new directions for the treatment of PAH and improve the long-term prognosis of PAH patients.

PCSK9 Inhibition Regulates Infarction-Induced Cardiac Myofibroblast Transdifferentiation via Notch1 Signaling.

Increasing evidence suggests that PCSK9 inhibition protects cardiomyocytes against ischemia-reperfusion injury after myocardial infarction. However, it is not clear whether PCSK9 inhibitor (PCSK9i) affects cardiac fibroblasts (CFs) activation after MI. In this study we used SBC-115076, an antagonist of PCSK9, to investigate the role of PCSK9i in the conversion of CFs to cardiac myofibroblasts (CMFs) after MI and provided a basic for its clinical application in cardiac fibrosis after MI. In vivo study, PCSK9i was injected into mice 4 days after MI. Cardiac function and degree of fibrosis were evaluated by echocardiographic and tissue staining after treatment. Western blot showed that PCSK9i treatment decreases expression of α-SMA, collagen and increases expression of Notch1 in border infarct area. Vitro studies showed that PCSK9i decreased the degree of fibrosis, migration, and collagen fiber deposition in CFs. Confocal microscopy imaging also showed that hypoxia contributes to the formation of α-SMA stress filaments, and PCSK9i alleviated this state. Moreover, overexpression of Notch1 further suppress the activation of CFs under hypoxia. These results revealed that SBC-115076 ameliorates cardiac fibrosis and ventricular dysfunction post-myocardial infarction through inhibition of the differentiation of cardiac fibroblasts to myofibroblasts via Notch1/Hes1 signaling.

Insights into the Molecular Mechanisms of NRF2 in Kidney Injury and Diseases.

Redox is a constant phenomenon in organisms. From the signaling pathway transduction to the oxidative stress during the inflammation and disease process, all are related to reduction-oxidation (redox). Nuclear factor erythroid 2-related factor 2 (NRF2) is a transcription factor targeting many antioxidant genes. In non-stressed conditions, NRF2 maintains the hemostasis of redox with housekeeping work. It expresses constitutively with basal activity, maintained by Kelch-like-ECH-associated protein 1 (KEAP1)-associated ubiquitination and degradation. When encountering stress, it can be up-regulated by several mechanisms to exert its anti-oxidative ability in diseases or inflammatory processes to protect tissues and organs from further damage. From acute kidney injury to chronic kidney diseases, such as diabetic nephropathy or glomerular disease, many results of studies have suggested that, as a master of regulating redox, NRF2 is a therapeutic option. It was not until the early termination of the clinical phase 3 trial of diabetic nephropathy due to heart failure as an unexpected side effect that we renewed our understanding of NRF2. NRF2 is not just a simple antioxidant capacity but has pleiotropic activities, harmful or helpful, depending on the conditions and backgrounds.

Discovery of compounds that reactivate p53 mutants in vitro and in vivo.

The tumor suppressor p53 is the most frequently mutated protein in human cancer. The majority of these mutations are missense mutations in the DNA binding domain of p53. Restoring p53 tumor suppressor function could have a major impact on the therapy for a wide range of cancers. Here we report a virtual screening approach that identified several small molecules with p53 reactivation activities. The UCI-LC0023 compound series was studied in detail and was shown to bind p53, induce a conformational change in mutant p53, restore the ability of p53 hotspot mutants to associate with chromatin, reestablish sequence-specific DNA binding of a p53 mutant in a reconstituted in vitro system, induce p53-dependent transcription programs, and prevent progression of tumors carrying mutant p53, but not p53null or p53WT alleles. Our study demonstrates feasibility of a computation-guided approach to identify small molecule corrector drugs for p53 hotspot mutations.

New Insights into the Treatment of Glomerular Diseases: When Mechanisms Become Vivid.

Treatment for glomerular diseases has been extrapolated from the experience of other autoimmune disorders while the underlying pathogenic mechanisms were still not well understood. As the classification of glomerular diseases was based on patterns of juries instead of mechanisms, treatments were typically the art of try and error. With the advancement of molecular biology, the role of the immune agent in glomerular diseases is becoming more evident. The four-hit theory based on the discovery of gd-IgA1 gives a more transparent outline of the pathogenesis of IgA nephropathy (IgAN), and dysregulation of Treg plays a crucial role in the pathogenesis of minimal change disease (MCD). An epoch-making breakthrough is the discovery of PLA2R antibodies in the primary membranous nephropathy (pMN). This is the first biomarker applied for precision medicine in kidney disease. Understanding the immune system's role in glomerular diseases allows the use of various immunosuppressants or other novel treatments, such as complement inhibitors, to treat glomerular diseases more reasonable. In this era of advocating personalized medicine, it is inevitable to develop precision medicine with mechanism-based novel biomarkers and novel therapies in kidney disease.

Relationship Between Serum Concentration of Adrenomedullin and Myocardial Ischemic T Wave Changes in Patients With Lung Cancer.

Background: Patients with lung cancer are at increased risk for the development of cardiovascular diseases. Molecular markers for early diagnosis of cardiac ischemia are of great significance for the early prevention of cardiovascular events in patients with lung cancer. By evaluating the relationship between adrenomedullin (ADM) and myocardial ischemic T wave changes, the clinical value of circulating ADM as a predictor of myocardial ischemia in patients with lung cancer is confirmed. Methods: We enrolled patients with lung cancer and healthy people from 2019 to 2021 and extracted a detailed ECG parameter. After adjustment for potential confounders, logistic regression was used to assess the association of clinical data. We performed analyses on differences in T wave between patients with lung cancer and healthy people, and the relationship between T wave and ADM among patients with lung cancer. Receiver operator characteristic (ROC) curves were drawn to confirm the diagnostic value of biomarkers. Results: After adjusting for potential confounders, the incidence of T wave inversion or flattening in patients with lung cancer was higher than in healthy people (OR: 3.3228, P = 0.02). Also, further analysis of the data of lung cancer patients revealed that the ADM in lung cancer patients with T wave inversion or flat was higher than those with normal T wave (189.8 ± 51.9 vs. 131.9 ± 38.4, p < 0.001). The area under the ROC curve was 0.8137. Conclusion: Among the patients with lung cancer, serum ADM concentration is associated with the incidence of the abnormal T wave. ADM might be a potentially valuable predictor for heart ischemia in patients with lung cancer.

Identification and expression pattern of the sex determination gene fruitless-like in Cherax quadricarinatus.

The fruitless (fru) gene has an important function in the courtship behavior and sex determination pathway of Drosophila melanogaster; however, the fru gene has never been reported in shrimps. In this study, the fruitless-like gene was identified in Cherax quadricarinatus (Cqfru) and is reported here for the first time. A sequence analysis revealed a conserved BTB domain in Cqfru which is the same as fru in D. melanogaster. An analysis of the expression level of Cqfru showed that it was highly expressed in the gastrula stage during embryonic development. Furthermore, in situ hybridization and expression distribution in tissues showed that its sexually dimorphic expression may be focused on the hepatopancreas, brains, and gonads. The gonads, brains, and hepatopancreas of males had a higher expression level of Cqfru than those of females; however, the expression level of the abdominal ganglion was found to be higher in females than in males in this study. The results of an RNA interference treatment showed that a knockdown of Cqfru reduced the expression of the insulin-like androgenic gland hormone (IAG) and tumor necrosis factor (TNF). The characteristic fru gene in shrimps is reported here for the first time, with the results providing basic information for research into the sex-determination mechanism in C. quadricarinatus.

Association of angiotensin-converting enzyme inhibitors or angiotensin II receptor antagonists use with risk of atrial fibrillation after pacemaker implantation among very old patients.

It remains unknown whether and to what extend the angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin receptor blockers (ARBs) can play a role in the development of atrial fibrillation (AF) after pacemaker implantation in very old patients. Therefore, we aimed to investigate the association between oral ACEIs or ARBs and the risk of developing AF in very old patients after pacemaker implantation. Patients above 80 years old with pacemaker implantation and without baseline history of AF were included and their real-world information about ACEIs or ARBs use was extracted from electronic medical records. New AF cases were confirmed via the records of outpatient visits. The multivariable Cox proportional-hazards model was used to evaluate the associations between oral ACEIs or ARBs and risk of AF after pacemaker implantation. Among a total of 388 identified patients aged 80 to 98 years, 118 used ACEIs, 174 had ARBs therapy, and 115 AF were identified after pacemaker implantation during a median follow-up time of 3.1 years. After adjustment for potential confounders, patients with daily use of ARBs had a relatively lower risk of AF after pacemaker implantation (HR: 0.627, 95% CI: 0.425, 0.926; P = 0.019) compared with those non-users, whereas ACEIs therapy didn't show a significant relation with AF risk (HR: 1.335, 95% CI: 0.894, 1.995; P = 0.157). In conclusion, for very old patients with a permanent pacemaker, daily use of oral ARBs was associated with a relative lower risk of AF after pacemaker implantation, however, daily use of ACEIs was not related with AF risk.

Neuregulin-1ß Alleviates Sepsis-Induced Skeletal Muscle Atrophy by Inhibiting Autophagy via AKT/mTOR Signaling Pathway in Rats.

BACKGROUND: Several studies have shown that excessive protein degradation is a major cause of skeletal muscle atrophy induced by sepsis, and autophagy is the main pathway participating in protein degradation. However, the role of autophagy in sepsis is still controversial. Previously, we found that neuregulin-1ß (NRG-1ß) alleviated sepsis-induced diaphragm atrophy through the phosphatidylinositol-3 kinase signaling pathway. Akt/mechanistic target of rapamycin (mTOR) is a classic signaling pathway to regulate autophagy, which maintains intracellular homeostasis. This study aimed to investigate whether NRG-1ß could alleviate sepsis-induced skeletal muscle atrophy by regulating autophagy. METHODS: L6 rat myoblast cells were differentiated using 2% fetal bovine serum into myotubes, which were divided into four groups: Con group treated with normal serum; Sep group treated with septic serum to form a sepsis cell model; septic serum + NRG-1ß (SN) group treated with septic serum for 24 h followed by injection with NRG-1ß and incubation for another 48 h; and serum+NRG-1ß+LY294002 group, in which the PI3K inhibitor LY294002 was added 30 min before NRG-1ß, and other treatments were similar to those in SN group. Effects of NRG-1ß were also evaluated in vivo using Sprague-Dawley (SD) rats, in which sepsis was induced by cecal ligation and puncture (CLP). RESULTS: In L6 myotubes treated with septic serum, the expression of autophagy-related proteins UNC-51 like kinase 1, p-Beclin-1, and Beclin-1, and the ratio of LC3B II/I were highly increased, while protein p62 expression was decreased, indicating that autophagy was excessively activated. Moreover, NRG-1 expression was decreased, as detected by confocal immunofluorescence and western blotting. Upon exogenous addition of NRG-1ß, autophagy was inhibited by the activation of Akt/mTOR signaling pathway, and cell viability was also increased. These effects disappeared in the presence of LY294002. In SD rats, sepsis was induced by CLP. NRG-1ß was shown to inhibit autophagy in these rats via the Akt/mTOR pathway, leading to increased body weight of the septic SD rats and alleviation of atrophy of the tibialis anterior muscle. CONCLUSION: NRG-1ß could alleviate sepsis-induced skeletal muscle atrophy by inhibiting autophagy via the AKT/mTOR signaling pathway.

Metabolic remodelling during early mouse embryo development.

During early mammalian embryogenesis, changes in cell growth and proliferation depend on strict genetic and metabolic instructions. However, our understanding of metabolic reprogramming and its influence on epigenetic regulation in early embryo development remains elusive. Here we show a comprehensive metabolomics profiling of key stages in mouse early development and the two-cell and blastocyst embryos, and we reconstructed the metabolic landscape through the transition from totipotency to pluripotency. Our integrated metabolomics and transcriptomics analysis shows that while two-cell embryos favour methionine, polyamine and glutathione metabolism and stay in a more reductive state, blastocyst embryos have higher metabolites related to the mitochondrial tricarboxylic acid cycle, and present a more oxidative state. Moreover, we identify a reciprocal relationship between α-ketoglutarate (α-KG) and the competitive inhibitor of α-KG-dependent dioxygenases, L-2-hydroxyglutarate (L-2-HG), where two-cell embryos inherited from oocytes and one-cell zygotes display higher L-2-HG, whereas blastocysts show higher α-KG. Lastly, increasing 2-HG availability impedes erasure of global histone methylation markers after fertilization. Together, our data demonstrate dynamic and interconnected metabolic, transcriptional and epigenetic network remodelling during early mouse embryo development.

Next-Generation Genome-Scale Metabolic Modeling through Integration of Regulatory Mechanisms.

Genome-scale metabolic models (GEMs) are powerful tools for understanding metabolism from a systems-level perspective. However, GEMs in their most basic form fail to account for cellular regulation. A diverse set of mechanisms regulate cellular metabolism, enabling organisms to respond to a wide range of conditions. This limitation of GEMs has prompted the development of new methods to integrate regulatory mechanisms, thereby enhancing the predictive capabilities and broadening the scope of GEMs. Here, we cover integrative models encompassing six types of regulatory mechanisms: transcriptional regulatory networks (TRNs), post-translational modifications (PTMs), epigenetics, protein-protein interactions and protein stability (PPIs/PS), allostery, and signaling networks. We discuss 22 integrative GEM modeling methods and how these have been used to simulate metabolic regulation during normal and pathological conditions. While these advances have been remarkable, there remains a need for comprehensive and widespread integration of regulatory constraints into GEMs. We conclude by discussing challenges in constructing GEMs with regulation and highlight areas that need to be addressed for the successful modeling of metabolic regulation. Next-generation integrative GEMs that incorporate multiple regulatory mechanisms and their crosstalk will be invaluable for discovering cell-type and disease-specific metabolic control mechanisms.

Localized Proteolysis for the Construction of Intracellular Asymmetry in Escherichia coli.

Protein-level regulations have gained importance in building synthetic circuits, as they offer a potential advantage in the speed of operation compared to gene regulation circuits. In nature, localized protein degradation is prevalent in polarizing cellular signaling. We, therefore, set out to systematically investigate whether localized proteolysis can be employed to construct intracellular asymmetry in Escherichia coli. We demonstrate that, by inserting a cognate cleavage site between the reporter and C-terminal degron, the unstable reporter can be stabilized in the presence of the tobacco etch virus protease. Furthermore, the split protease can be functionally reconstituted by the PopZ-based polarity system to exert localized proteolysis. Selective stabilization of the unstable reporter at the PopZ pole can lead to intracellular asymmetry in E. coli. Our study provides complementary evidence to support that localized proteolysis may be a strategy for polarization in developmental cell biology. Circuits designed in this study may also help to expand the synthetic biology repository for the engineering of synthetic morphogenesis, particularly for processes that require rapid control of local protein abundance.

New progress in elucidating the relationship between cancer therapy and cardiovascular toxicity.

Onco-cardiology is an emerging field linking cancer with cardiovascular injury. Understanding the mechanism of cardiac injury helps improve the quality of life of cancer survivors. A series of studies on adverse reactions to cancer or oncological treatments has indicated that adverse cardiovascular events related to cancer treatments may occur over a longer period of survival, and even years after therapy has concluded. Current cancer therapies, including chemotherapy, radiotherapy, targeted therapy, and immunotherapy, have been found to have latent cardiovascular toxicity. These toxic effects are often progressive and irreversible and ultimately lead to cardiovascular events such as heart failure, hypertension, coronary heart diseases, arrhythmia, and thromboembolism. Therefore, more emphasis should be placed on revealing the mechanism of cancer treatment-related cardiovascular toxicity. This would help to guide prevention, diagnosis, and treatment of CVDs in cancer survivors.

Association of furosemide or hydrochlorothiazide use with risk of atrial fibrillation post pacemaker implantation among elderly patients.

BACKGROUND: Atrial fibrillation (AF) induced by artificial pacing is directly related to atrial remodeling. Previous basic research has shown that furosemide aggravates pathologic myocardial remodeling while hydrochlorothiazide alleviates it. However, whether furosemide or hydrochlorothiazide plays a role in developing AF after pacemaker implantation remains unknown. The study aims to investigate the association between oral furosemide or hydrochlorothiazide and the risk of developing AF after pacemaker implantation. METHODS: After a review of electronic medical records, elderly patients with pacemaker implantation and without a known baseline history of AF were included and information on their use of daily oral furosemide or hydrochlorothiazide was extracted. New incident AF cases were confirmed via the records of outpatient visits. A Cox proportional-hazards model was used to evaluate the association between daily oral furosemide or hydrochlorothiazide and risk of developing AF after pacemaker implantation, after adjustment for potential confounders. RESULTS: Among a total of 551 patients aged more than 65 years, 157 AF cases were identified after pacemaker implantation during a maximum follow up of 3.0±1.6 years. Of these, 242 had used furosemide and 97 had used hydrochlorothiazide therapy. Patients taking daily oral furosemide had a relatively higher risk of AF after pacemaker implantation [hazard ratio (HR): 1.507, 95% confidence interval (CI): 1.036-2.192; P=0.032] after being adjusted for related disease and prescribed medications, while oral taking of hydrochlorothiazide was shown to be a non-effective factor (HR: 0.666, 95% CI: 0.413-1.074), which had no statistical significance. CONCLUSIONS: Daily oral furosemide might increase the risk of developing AF after pacemaker implantation in elderly patients, while hydrochlorothiazide has no detrimental effect.

Lipid remodeling in response to methionine stress in MDA-MBA-468 triple-negative breast cancer cells.

Methionine (Met) is an essential amino acid and critical precursor to the cellular methyl donor S-adenosylmethionine. Unlike nontransformed cells, cancer cells have a unique metabolic requirement for Met and are unable to proliferate in growth media where Met is replaced with its metabolic precursor, homocysteine. This metabolic vulnerability is common among cancer cells regardless of tissue origin and is known as "methionine dependence", "methionine stress sensitivity", or the Hoffman effect. The response of lipids to Met stress, however, is not well-understood. Using mass spectroscopy, label-free vibrational microscopy, and next-generation sequencing, we characterize the response of lipids to Met stress in the triple-negative breast cancer cell line MDA-MB-468 and its Met stress insensitive derivative, MDA-MB-468res-R8. Lipidome analysis identified an immediate, global decrease in lipid abundances with the exception of triglycerides and an increase in lipid droplets in response to Met stress specifically in MDA-MB-468 cells. Furthermore, specific gene expression changes were observed as a secondary response to Met stress in MDA-MB-468, resulting in a downregulation of fatty acid metabolic genes and an upregulation of genes in the unfolded protein response pathway. We conclude that the extensive changes in lipid abundance during Met stress is a direct consequence of the modified metabolic profile previously described in Met stress-sensitive cells. The changes in lipid abundance likely results in changes in membrane composition inducing the unfolded protein response we observe.